Perhaps by having strong friendships come into play. If the story shows that Fred or other friends are desperately trying to save Hermione, it gives the reader hope. Like, Fred could be rallying the other Weasleys and Hogwarts students to find a way to rescue her from the torturous situation.
The author could also use flashbacks of Hermione's happy memories. These could be her times at Hogwarts studying in the library, or her adventures with Harry and Ron. By interspersing these positive memories during the torture scenes, it softens the harshness of the plot.
Fred could use his knowledge of the Weasley family's magic tricks and inventions. He might have some secret gadget or spell that can break through the barriers or spells that are being used to torture Hermione.
Joining Harry Potter fan groups on social media platforms can also be helpful. People in these groups often share and recommend good fanfictions. You can ask specifically for 'Fred and Hermione pregnant' fanfictions, and they might point you to some great reads.
Maybe introduce a deus ex machina element. For instance, just when it seems the torture is getting too much, a powerful magical creature appears and scares Bellatrix away. This would lighten the mood a bit and prevent the story from going into extremely dark territory. Also, the author could play with the idea of Hermione having some sort of pre - prepared magical protection that lessens the impact of the torture.
Well, in some versions, Fred might use his quick-witted magic skills. He could cast a distraction spell to draw Bellatrix's attention away from Hermione. Maybe a spell that creates multiple illusions of himself, confusing Bellatrix long enough for him to grab Hermione and disapparate them to safety.
You can focus on adding elements of hope or redemption. Even in the midst of sadness, showing that there's a glimmer of a better future can make it more bearable.
In fanfiction, Fred's worry about Hermione breaking her arm can be a catalyst for character growth. His worry forces him to face his feelings for Hermione. This internal struggle can add depth to the plot. He may also become more assertive in trying to keep Hermione safe, which could lead to conflicts with other characters who have different ideas about how to handle the situation. This can create a complex web of relationships and events that drive the story forward.
It can't really be made acceptable as the concept of slavery is fundamentally wrong. However, if one were to re - concept the idea completely away from slavery. For example, if it was about Hermione helping a group of oppressed women gain their freedom and rights, and then building a positive relationship with them, that would be a different and more acceptable story.
To make Hermione's bossy trait more appealing in fanfiction, the writer can link it to her intelligence. Maybe she's bossy because she has a clear vision of how things should be done based on her extensive knowledge. Also, showing her vulnerability when her bossy plans don't work out can make readers empathize with her more. It gives her more depth as a character and makes her bossiness seem less off - putting.
It could also be that they run away for a more personal reason. Maybe Fred has feelings for Hermione that go against the social norms in the wizarding community. They run away to be together and explore their relationship away from the prying eyes and judgmental attitudes of their friends and family.
Well, it could be a story where there's a big misunderstanding. Maybe Hermione thought Fred was about to play a prank on her that would cause harm to someone, and in her haste to stop him, she accidentally kicks him in the balls. Then it might lead to a whole series of events like Hermione feeling extremely guilty and trying to make it up to Fred while Fred is initially angry but then realizes it was a mistake.